Cranks but won't start?

[oregon101]

I need some advice. I have a 89 7.3 that is giving me problems. I've driven it about 2,000 miles since I bought it with no problems until now. It cranks fine {new batteries and starter} but won't fire. The glow plug controller is bad so since I've had it I give it a short burst of starting fluid when cold to get it going. Last week driving to work the truck died on me twice going to work when I came to a stop. It restarted each time and I got to work. Now the truck won't start. I installed a new fuel filter no change. I cracked open the line coming out of the fuel filter to the IP and I'm getting fuel out but not real fast. It doesn't spray out it's more like a steady flow. I'm thinking the fuel pump is not giving enough flow. Any other ideas? Thanks.

 

[funnyman06]

sounds like a possible IP problem. Have you checked the fuel filter, made sure there is fuel in it and maybe replace it.

 

[towcat]

start with the basics.
change the fuel filter. as per your description, restricted fuel flow is the first culprit. move up from there.
fuel fiter $18.
fuel pump $35
injection pump $400
get the idea?

 

[oregon101]

How much fuel flow should come off the filter head? I push in the bleed valve on the fuel filter head and get a small flow out but there isn't much pressure. I did prefill the filter before installing it.

 

[argve]

you mention that it wanted to die when rolling up to stop (returning to idle) that is typically a sign that the metering valve in the injection pump is dieing which leads me to believe that the problem lies in your injection pump.

with the key ON pop open the hood and disconnect and reconnect the fuel shut off solenoid and listen carefully for a Click as the connection is made. If you heard the click then you know that the FSS is getting power (power has to be applied for it to allow fuel to flow through the injection pump).

If you have the "click" then unscrew on of the lines going to an injector and have some one crank the engine over and look for some fuel to come out - now it's not going to be tons of fuel because at idle your not pushing much VOLUME it's more of a pressure thing. That will tell us if you have fuel going to the injectors and making it totally through the injection pump. If you have fuel to the injectors then it's either a cranking issue (not cranking fast enough or because your glow plugs aren't working you don't have enough heat to ignite the fuel). I doubt it will be the cranking speed since you just replaced the starter.

Now guys he did mention that he replaced the fuel filter already.

 

[argve]

The mechanical fuel pump on the side of the block won't create a lot of pressure (7-9psi if memory serves). You won't get a lot of flow out of the schrader valve but if you are getting fuel then I would say keep looking else where for the problem.

 

[oregon101]

I just attached a pressure gauge to the schrader valve on the fuel filter head and while cranking it would not even read any pressure.

 

[argve]

you should see some pressure there.

 

[oregon101]

I think it's time to put on a new fuel pump. Any suggestions before I start?

 

[hoodshauler]

Have you checked to see if there is fuel at the injectors. Do all the free checks first. hate to see you spend money on stuff you don't need

 

[Papabear]

have you eliminated the possibility of it being the pickup pump?

 

[jw2644]

Sounds like a pickup pump to me if you don't have any pressure at the filter

 

[oregon101]

Well it's alive! I installed a remote filter base outside the fuel tank and installed a Holley red fuel pump bypassing the mech. pump for now. It fired up after I cleared the air from the lines. It still takes a minute to warm up and stay at idle when cold. Any ideas on that? I'm playing around with running waste oil in it that's why the second filter and electric pump. Should I go ahead and install a new mech. pump or just run on only the Holley pump? Will it hurt anything having both the Holley pump and a mech. pump?

 

[icanfixall]

Yes... Don't run the Holley into the mechanical. The daiphram in the mechanical will break and then you dilute the motor oil will diesel. That will wipe the bearings in short order.

 

[oregon101]

The Holley only puts out 7-9psi. I didn't think that would be enough to ruin the mech. pump?